Mid-range hesitation

[RaWarrior]

I've got this little problem with my '97 that kind of comes and goes on a pretty random basis.

At highway speeds(say 55 and up), sometimes the throttle acts like it hits a "dead spot" when I go to roll on the gas. To put it another way, slight increases in throttle have virtually no effect. If I continue to slowly roll on, by maybe half-2/3 throttle all of a sudden it takes off and runs fine. Getting the RPMs up doesn't seem to make much of a difference, I can be cruising at 90 and get the same "lag". Past 6k with vboost, it seems to stop, and if I switch the t-boost to 3k(to open the valves), that usually clears it up. When the "lag" occurs, it almost feels like one cylinder is not firing.

The p/o installed a Stage 1 kit, and a K&N filter. Stock headers, holeshot s/o's. Nology coils, NGK wires/caps, and NGK Iridium plugs.

I've tried both the peashooter and shotgun...neither seemed to make much of a difference. However, when I drained the bowls a relatively large amount of water came out of one carb bowl...the other 3 were fine. It was the right-rear carb. Checking the plugs, they all look the same. To my eye they seemed maybe a teensy bit lean, there was just a "hint" of tan color on the insulator. Otherwise the bike runs awesome. Smooth steady idle, no starting problems, loads of power. Never overheats, or even comes close to the red zone on the temp. With the fan running it NEVER goes past half way on the temp gauge.

I've tried using sea-foam, the blue sta-bil, and other fuel additives with fill-ups. Since the problem is intermittent, it's difficult to tell if a period with no lag is from the additive or just chance. Note: all gas around here is E10. The marina where I work recently got ethanol-free gas, so I'll try running that to see if it makes a difference.

Since the shotgun, it seems to maybe have gotten better.....subjectively it happens less often and the "lag" isn't as pronounced.

Eagle recently had his carbs redone, and mentioned that he had a "stumble" between 4-6k....similar to my problem. He said that adding one washer to the needles solved it. I'm not so good with CV type carbs, so correct me if I'm wrong, but adding a washer would "lift" the needle a bit more, and make the bike a bit richer? That could explain the lean looking plugs, and why activating v-boost clears the issue up. A lean midrange? Last question: where would I get washers for the needles to try this?

 

[gamorg02]

hey ryan.

you're right on on the needles richening up the midrange, can't hurt to try. I got the shims in my jet kit but also used some from radio shack. the $1.99 100 pack of washers have a one size thats the right kind. just make sure they're flat and have the same thickness. i believe thats ~0.020"

i'd say start there. thats right in the needle range. u have adjustable needles too probably. you can try just moving the clip down one (raising the needle). the shims are roughly 1/2 a clip.

 

[naughtyG]

Yup, as you have a DJ Stage 1 you should have adjustable needles. Two things:

- most people reckon the Stage 1's a waste of time. Did you get the stock needles from the PO? If yes, I would try that first.

- if you don't, just go ahead and adjust your needle clips. It's piss easy. Remove the carb covers (do one at a time), watch out for that big spring jumping out. Then pull out the slide and needle. Pull the needle out of the side, and move the clip one notch toward the pointy end of the needle. Do all four, then go ride, see if it helps. It will indeed richen your mixture in the rpm range you're feeling your stumble in. If it gets worse, try moving the clips one notch the other way.

 

[gamorg02]

sometimes putting on the choke every so lightly can tell you if your running rich or lean on the fly..

 

[davidon]

I've got some saved emails from Terry Campbell about carb that I have to scan so they can be archived..for midrange problems he recommends doing a test at 4K to WOT..cruise at 4k and then go to WOT..if there is any hesitation need to adjust needle clip position.

 

[tugla]

too bad we didnt know about it on the brownie run ryan, thats what i was playing with on mine.
also i found that e10 shit really made my bike run weird, when i got it back over the boarder and straight fuel started to run way way better, like a raped ape in the evenings, didnt think the e10 effected it that much but i guess it does, runs smother and smother without that, so if you can find a station without it for sure run that stuff.

 

[jfeagins]

too bad we didnt know about it on the brownie run ryan, thats what i was playing with on mine.
also i found that e10 shit really made my bike run weird, when i got it back over the boarder and straight fuel started to run way way better, like a raped ape in the evenings, didnt think the e10 effected it that much but i guess it does, runs smother and smother without that, so if you can find a station without it for sure run that stuff.

+1000000


Getting harder and harder to find 100% pure gasoline in the US due to Federal mandates for the industry.

 

[RaWarrior]

No, I got a lot of stock parts with my Max, but carb bits weren't among them. The p/o said the stage 1 "really perked the bike up", he said it also make the bike run generally cooler....I have no comparison

If I'm going 4k in 5th gear and snap it WOT, it takes off great. It's slight movements that either seem to cause the hesitation, or make it noticeable.

Thinking a little more, it almost seems the slides are sticking, and once the vacuum builds up enough in the manifold from rolling on the gas, they suddenly "snap" open. When I did the shotgun I sprayed them with WD40 before reinstalling, and at idle when looking they all seem to move freely with revving. It's the fact that the issue comes and goes that puzzles me and makes the think it has to be a fuel issue.

I'll get my bike back Wednesday night(left it with a friend at home to get the tires changed....stupid Avon was showing LOTS of cords at 6000 miles), and I'll play with it then.

I'm going to check the bowls again for any water. Working on boats, I know that water can be tough to get rid of, and that "recommended" doses of additives don't always take care of it. Typically have good luck running the tank down low, adding a mega-dose of isopropyl, then running it virtually bone dry and refilling with the ethanol-free. That will tell me if it's a problem from bad gas. If that doesn't help, then it's my carbs, and I'll move the clips in one notch and try again.

E10 is still being pushed into gas, despite the whole ethanol craze blowing over. 10% ethanol is just enough to cause problems in motors, but the savings on emissions are so insignificant, and it's been proven that the reduced mileage of e10 outweighs the reduced emissions. It burns slightly cleaner, but you burn more of it, which more than cancels it out. Unfortunately all the corn farmers have a powerful lobby and want their government subsidies to pour that shit into our gas.

 

[maleko89]

If you have the stock exhaust and air box then remove stage 1. I'd be suspect of Nology coils too since they are generally a piece of shit. Wires are a waste too. With as much as they sell those for you'd thing they are using HD philosophy.

 

[tugla]

No, I got a lot of stock parts with my Max, but carb bits weren't among them. The p/o said the stage 1 "really perked the bike up", he said it also make the bike run generally cooler....I have no comparison

If I'm going 4k in 5th gear and snap it WOT, it takes off great. It's slight movements that either seem to cause the hesitation, or make it noticeable.

Thinking a little more, it almost seems the slides are sticking, and once the vacuum builds up enough in the manifold from rolling on the gas, they suddenly "snap" open. When I did the shotgun I sprayed them with WD40 before reinstalling, and at idle when looking they all seem to move freely with revving. It's the fact that the issue comes and goes that puzzles me and makes the think it has to be a fuel issue.

I'll get my bike back Wednesday night(left it with a friend at home to get the tires changed....stupid Avon was showing LOTS of cords at 6000 miles), and I'll play with it then.

I'm going to check the bowls again for any water. Working on boats, I know that water can be tough to get rid of, and that "recommended" doses of additives don't always take care of it. Typically have good luck running the tank down low, adding a mega-dose of isopropyl, then running it virtually bone dry and refilling with the ethanol-free. That will tell me if it's a problem from bad gas. If that doesn't help, then it's my carbs, and I'll move the clips in one notch and try again.

E10 is still being pushed into gas, despite the whole ethanol craze blowing over. 10% ethanol is just enough to cause problems in motors, but the savings on emissions are so insignificant, and it's been proven that the reduced mileage of e10 outweighs the reduced emissions. It burns slightly cleaner, but you burn more of it, which more than cancels it out. Unfortunately all the corn farmers have a powerful lobby and want their government subsidies to pour that shit into our gas.

have you synced it lately man??? thats what i was spending soo much time on, it drives me crazy if the throttle response is all wrong, got to be instant with the slightest twist. just to make sure its all good id sync them, check all a/f screws are the same or close. wish i was back home in mtl i have a set of stock needles i could have sent to you. let me work on that might be able to have someone send them if they can find it in my mess of parts. otherwise some shims will help you out. also check for any vacuum leaks or loose clamps etc. all the little things add up and mess it up

 

[gamorg02]

Ryan,

Tugla brings up a good point. I have a set of stock needles you could use to see if they help.. if ur interested PM me..

 

[tugla]

guess you also didnt like the avon tires ey ryan, noticed how they were looking a little think in the rear hahahah did you get a 170 tire this time???

 

[RaWarrior]

Yeah, I went with a 170/80 rear and 110/90 front, both Metzeler ME880's.

I wouldn't have gone for the aftermarket coils/wires and such, I know how pricey that stuff is for absolutely no real-world gain. It all came with the bike, and I didn't get the stock ones. I had considered maybe a spark issue from one of the coils beginning to crap out, but in my experience bad coils typically show problems in the high range when demand is highest. New wires? Probably a waste of money, but they can't really hurt anything.

I did do a sync recently. Maybe smoothed out the idle a bit, but they really weren't that far off to start, all within about 1 in/Hg each other. When I did the shotgun, all the needles were between 2 7/8 and 3 turns out, so when I put them back in I set them all to 3 turns out. Idles great, and those screws only control the idle circuit, right?

Now I finally have something to fiddle with, and my Max is at home. I'll try moving the clips first on these needles, and if I still can't figure it out then I'll see about getting stock needles. I just can't get over that it has to be a fuel issue since the problem comes and goes.

 

[tugla]

Yeah, I went with a 170/80 rear and 110/90 front, both Metzeler ME880's.

I wouldn't have gone for the aftermarket coils/wires and such, I know how pricey that stuff is for absolutely no real-world gain. It all came with the bike, and I didn't get the stock ones. I had considered maybe a spark issue from one of the coils beginning to crap out, but in my experience bad coils typically show problems in the high range when demand is highest. New wires? Probably a waste of money, but they can't really hurt anything.

I did do a sync recently. Maybe smoothed out the idle a bit, but they really weren't that far off to start, all within about 1 in/Hg each other. When I did the shotgun, all the needles were between 2 7/8 and 3 turns out, so when I put them back in I set them all to 3 turns out. Idles great, and those screws only control the idle circuit, right?

Now I finally have something to fiddle with, and my Max is at home. I'll try moving the clips first on these needles, and if I still can't figure it out then I'll see about getting stock needles. I just can't get over that it has to be a fuel issue since the problem comes and goes.

your right could be something else but too many variables, need to start somewhere and make sure everything is right, so once you know the carbs are good and thats not causing you grief then try ignition unless you feel its that from the beginning. does it have any hesitation/hick-up(like a miss fire) when cruising at a constant throttle setting like around 4 or 4500?
how the plugs look

 

[Rhoy Carter]

Also check the little o ring under the slide cover

 

[RaWarrior]

All the o-rings were there and fine, I was careful to watch them re-installing the covers.

At constant throttle in the 4-4500 range it seems to be running OK, but it's tough to tell. If I start to go up a hill or something and slightly roll on, it will still be losing speed until I crank the gas and it takes off. There's no popping or backfiring. Then a few minutes later it can be super-crisp on response again with zero lag, then back again. It's pretty random in duration and occurrence.

To my eye, when I checked a plug it looked kind of lean. Just a tiny ring of golden brown on the insulator around the electrode, the rest was grayish-white. Lean looking plugs would agree with having needles too far down, since the vast majority of the engine's runtime is on the highway, in the midrange. However as I said, it never has issues with overheating and from what I've gathered runs cooler than most Max's out there....never comes even near the red zone on the temp gauge, even in traffic.

 

[RaWarrior]

OK, update time. On the DJ needles, the clips were in the 4th slot (of 6) away from the pointy end. I moved them in to the third. Diaphragms all looked good, all o-rings there and fine. Drained the bowls, no water in sight.

Went for a ride...the mid-range is overall stronger, but there is still a distinct lag that comes and goes randomly like before. My Max has always run pretty cool, and now it's even cooler...it was only about 60 degrees out and the temp barely hit the one hashmark above the "cold" line on the highway. When I filled up I added some seafoam, which made zero difference, so I don't think it's a fuel issue now.

The random coming/going now has me thinking the coils could be suspect (since I really can't think of anything else.... If it was a carb issue it would be like that all the time right?) Looking into it, seems like everybody trashes Nology as being expensive garbage and there's tons of reports of motors running worse after installing them than before.

Anybody have a pair of good stock coils they want to part with for a reasonable price?

 

[veebooster]

Try the COPs mod.

Dale #2592

 

[tugla]

id give sean a call, he might have some coils you could use to try and then if it is buy them.

 

[naughtyG]

I have a set of coils for sale. They do have lil' cracks underneath in the plastic, but most people think they make no difference, and can be sealed with JBweld or similar.

If interested, make me an offer - I'll let them go cheap.

http://cgi.ebay.com/ebaymotors/ws/e...512099918&viewitem=&sspagename=STRK:MESELX:IT

Also, you may want to start by removing your HT leads, cutting about 1/4-1/2" of each end (provided you have enough length), then refitting in coils and spark plug caps. Those ends often corrode over time.

If still no joy, talk to Sean Morley about a replacement TCI unit to test if yours is the problem. Of course a great idea would be to also check all electrical connections in your ignition, making sure they're clean, free of corrosion, and add a wee bit dielectric grease.